Biomarkers for post-traumatic stress states

ABSTRACT

The present invention relates generally to the detection or diagnosis of post-traumatic stress states in a subject, and provides methods, reagents, and kits useful for this purpose. Provided herein are biomarkers that are indicative of and/or diagnostic of post-traumatic stress states including PTSD.

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 61/915,861, filed Dec. 13, 2013, the disclosure ofwhich is herein incorporated by reference in its entirety.

STATEMENT REGARDING FEDERAL FUNDING

This invention was made with government support under R21 MH077234awarded by the National Institutes of Health. The government has certainrights in the invention.

FIELD

The present invention relates generally to the detection or diagnosis ofpost-traumatic stress states in a subject, and provides methods,reagents, and kits useful for this purpose. Provided herein arebiomarkers that are indicative of and/or diagnostic of post-traumaticstress states including PTSD.

BACKGROUND

Approximately 6.8% of persons in the United States developpost-traumatic stress states, or as it is most commonly known PTSD, atsome time in their lives. Experiences that most often give rise to PTSDinclude rape, assault, and combat; natural disasters or man-madeaccidents. More than 20 percent of the troops who fought in the Iraq andAfghanistan wars may be diagnosed with PTSD. PTSD is a condition thatoccurs following exposure to an extremely traumatic experience thatresults in an intense and prolonged response to stress. Most individualswho experience a traumatic event at some time during their lives willrecover. A subset of individuals, however, develop PTSD. Biomarkers thatdiagnose and approximate PTSD risk would be of great value. Biomarkerdiscovery in PTSD has been hindered by the lack of prospective studiesin traumatized individuals.

SUMMARY

The present invention relates generally to the detection or diagnosis ofpost-traumatic stress states in a subject, and provides methods,reagents, and kits useful for this purpose. Provided herein arebiomarkers that are indicative of and/or diagnostic of post-traumaticstress states including PTSD.

In some embodiments, the present invention provides methods forcharacterizing a subject as suffering from post-traumatic stressdisorder, comprising: (a) detecting, in a sample obtained from thesubject, the levels of expression products of a panel of multiplebiomarkers selected from the genes listed in Table 1 (e.g., usingreagents and analytical techniques described herein); and (b)characterizing the risk of post-traumatic stress disorders in thesubject based on the levels of the expression products. In someembodiments, a subject is diagnosed as having a post-traumatic stressdisorder. In some embodiments, methods further comprise taking one ormore intervention steps to treat or prevent the post-traumatic stressdisorder. In some embodiments, methods further comprise subsequentre-testing for biomakers of post-traumatic stress disorder (e.g., aftertreatment, after a particular time period (e.g., 1 week, 1 month, 6months, 1 year, 2 years, etc.). In some embodiments, the subject is ahuman subject. In some embodiments, the sample is a tissue or fluid(e.g., urine, blood, saliva, etc.) sample. In some embodiments, thesample is a blood sample (e.g., whole blood, plasma, processed blood,etc.). In some embodiments, the human subject is suspected of sufferingfrom PTSD based on the presence of symptoms of PTSD, a prior traumaticevent or series of events, or a combination thereof.

In some embodiments, the panel of biomarkers comprises one or more(e.g., 1, 2, 3) of SERPINB1, LILRB3, and GLRX. In some embodiments, thepanel of biomarkers comprises one or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11) of IFI27, FUOM, HSPA8, IGK, LCMT1, THYN1, SEC14L2, SLC16A3,SERINC2, TRPM6, and XKRX. In some embodiments, the panel furthercomprises one or more of CYP21A1, ADN, DGAT2, PROK2, TNFRSF1A andELOVL5. In some embodiments, the panel of biomarkers comprises one ormore of IFI27, FUOM, HSPA8, IGK, LCMT1, THYN1, SEC14L2, SLC16A3,SERINC2, TRPM6, XKRX, CYP21A1, ADN, DGAT2, PROK2, TNFRSF1A and ELOVL5.In some embodiments, the panel of PTSD biomarkers comprises or consistsof 100 or fewer PTSD biomarkers (e.g., <100 biomarkers, <50 biomarkers,<40 biomarkers, <30 biomarkers, <20 biomarkers, <10 biomarkers). In someembodiments, the panel of PTSD biomarkers comprises or consists of twoof more PTSD biomarkers (e.g., >3 biomarkers, >4 biomarkers, >5biomarkers, >6 biomarkers, >7 biomarkers, >8 biomarkers, >9biomarkers, >10 biomarkers, >15 biomarkers, >20 biomarkers, >30biomarkers, >40 biomarkers). In some embodiments, the PTSD panel is partof a larger panel of biomarkers (e.g., a panel that also screens forother diseases or conditions). In some embodiments, the PTSD panel ispart of a larger general panel of biomarkers, wherein the general panelcomprises or consists of 10,000 or fewer biomarkers (e.g., <5,000biomarkers, <1,000 biomarkers, <500 biomarkers, <200 biomarkers, <100biomarker, <50 biomarkers, etc.).

In some embodiments, expression products are mRNAs corresponding to thebiomakers of the panel. In some embodiments, detecting the levels ofexpression products comprises exposing the sample to nucleic acid probescomplementary to the mRNAs corresponding to the biomarkers of the panel.In some embodiments, nucleic acid probes are covalently linked to asolid surface. In some embodiments, detecting the levels of expressionproducts comprises use of a detection technique selected from the groupconsisting of microarry analysis, reverse transcriptase PCR,quantitative reverse transcriptase PCR, and hybridzation analysis.

In some embodiments, detection of expression products comprisesgeneration of cDNA (e.g., by reverse transcription) from the mRNA (e.g.,biomarker mRNA) in a sample, and detecting the cDNA. In someembodiments, cDNA are full-length cDNA. In some embodiments, cDNA isfurther amplified prior to detection (e.g., by qPCR). In someembodiments, reverse-transcriptase PCR (RT-PCR) is used to detect theexpression of RNA. In RT-PCR, RNA is enzymatically converted tocomplementary DNA or “cDNA” using a reverse transcriptase enzyme. ThecDNA may be detected or used as a template for a PCR reaction. PCRproducts can be detected by any suitable method, including but notlimited to, gel electrophoresis and staining with a DNA specific stainor hybridization to a labeled probe. In some embodiments, thequantitative reverse transcriptase PCR with standardized mixtures ofcompetitive templates method described in U.S. Pat. Nos. 5,639,606,5,643,765, and 5,876,978 (each of which is herein incorporated byreference) is utilized.

In some embodiments, expression products are proteins corresponding tothe biomarkers of the panel. In some embodiments, detecting the levelsof expression products comprises exposing the sample to antibodies forthe proteins corresponding to the biomarkers of the panel. In someembodiments, antibodies are covalently linked to a solid surface. Insome embodiments, detecting the levels of expression products comprisesexposing the sample to a mass analysis technique (e.g., massspectrometry).

In some embodiments, the present invention provides kits, reagentmixtures, and/or surfaces comprising (or displaying) reagents fordetecting a panel of multiple biomarkers listed in Table 1. In someembodiments, reagents are provided for detection of 100 or fewer PTSDbiomarkers (e.g., <100 biomarkers, <50 biomarkers, <40 biomarkers, <30biomarkers, <20 biomarkers, <10 biomarkers). In some embodiments,reagents are provided for detection of two of more PTSD biomarkers(e.g., >3 biomarkers, >4 biomarkers, >5 biomarkers, >6 biomarkers, >7biomarkers, >8 biomarkers, >9 biomarkers, >10 biomarkers, >15biomarkers, >20 biomarkers, >30 biomarkers, >40 biomarkers). In someembodiments, the PTSD detecting reagents are provided with reagents fordetection of other non-PTSD biomarkers (e.g., biomarkers that for otherdiseases or conditions). In some embodiments, reagents are proved fordetecting less than 10,000 PTSD biomarkers and non-PTSD biomarkerscombined (e.g., <5,000 biomarkers, <1,000 biomarkers, <500 biomarkers,<200 biomarkers, <100 biomarker, <50 biomarkers, etc.).

In some embodiments, reagents are provided to detect a panel of PTSDbiomarkers comprising one or more of SERPINB1, LILRB3, and GLRX. In someembodiments, reagents are provided to detect a panel of PTSD biomarkerscomprising one or more of IFI27, FUOM, HSPA8, IGK, LCMT1, THYN1,SEC14L2, SLC16A3, SERINC2, TRPM6, and XKRX. In some embodiments, thepanel further comprises one or more of CYP21A1, ADN, DGAT2, PROK2,TNFRSF1A and ELOVL5. In some embodiments, reagents are provided todetect a panel of PTSD biomarkers comprising one or more of IFI27, FUOM,HSPA8, IGK, LCMT1, THYN1, SEC14L2, SLC16A3, SERINC2, TRPM6, XKRX,CYP21A1, ADN, DGAT2, PROK2, TNFRSF1A and ELOVL5.

In some embodiments, reagents are provided for the detection and/orquantification of biomarker proteins. Suitable reagents include primaryantibodies (e.g., that bind to the biomarkers), secondary antibodies(e.g., that bind primary antibodies), antibody fragments, aptamers, etc.Protein detection reagents may be labeled (e.g., fluorescently) orunlabeled, and may by free in solution or immobilized.

In some embodiments, reagents are provided for the detection and/orquantification of biomarker protein (e.g., mRNA). Suitable reagentsinclude amplification and/or detection reagents, such as primers and/orprobes. Primers and probes may be labeled (e.g., fluorescently) orunlabeled, and may by free in solution or immobilized.

In some embodiments, the present invention provides methods comprising:(a) receiving a sample obtained from a subject; (b) detecting in thesample one or more biomarkers listed in Table 1; and (c) converting thedata generated in step (b) into a PTSD risk assessment for the humansubject. In some embodiments, additional steps are performed, includingbut not limited to one or more of: generating a report, diagnosing thesubject with PTSD, recommending a course of therapy, administering atherapy (e.g., treating with a drug, treating with psychotherapy, etc.),etc.

In some embodiments, the present invention provides methods forcharacterizing a sample as having been obtained from a human subjectsuffering from PTSD, the method comprising one or more (e.g., all) ofthe steps of: (a) receiving a sample obtained from the subject; (b)detecting in the sample the level of a first biomarker of PTSD selectedfrom the biomarkers listed in Table 1; (c) detecting in the sample thelevel of at least a second biomarker of PTSD selected from thebiomarkers listed in Table 1; (d) using a computer-based analysisprogram is used to convert the data generated in steps (b) and (c) intoa PTSD risk assessment for the human subject from which the sample wasobtained; and (e) generating a report characterizing the sample ashaving been obtained from a human subject likely suffering from PTSDbased on the risk assessment of step (d).

In some embodiments, the present invention provides methods of testing asubject for PTSD, comprising: (a) obtaining a sample from the subject;(b) providing (e.g., delivering, shipping, etc.) the sample to testingfacility to be tested for levels expression products corresponding to apanel of multiple biomarkers listed in Table 1; and (c) receiving areport from the testing facility indicating the likelihood of thesubject suffering from PTSD. In some embodiments, methods furthercomprise a step of providing a kit to collect the samples.

A method of detecting determining the levels of one or more biomarkerslisted in Table 1 in a biological sample from a subject suffering from apost-traumatic stress state, the method comprising: quantifying thelevels of the one or more biomarkers listed in Table 1 in the biologicalsample from said subject suffering from a post-traumatic stress state.In some embodiments, quantifying the levels of the one or morebiomarkers listed in Table 1 comprises determining the level orconcentration of the biomarkers. In some embodiments, quantifying thelevels of expression of the one or more biomarkers listed in Table 1comprises determining the level or concentration of the biomarkers. Insome embodiments, the biomarker RNA is quantified. In some embodiments,the biomarker protein is quantified. In some embodiments, the biologicalsample is blood or saliva.

A method of treating post-traumatic stress in a subject comprising (a)determining the levels of one or more biomarkers listed in Table 1 in abiological sample from a subject, and (b) administering a therapy forpost-traumatic stress. In some embodiments, therapy is selected from thegroup consisting of psychoanalysis, psychotherapy, and pharmacologicaltreatment.

In some embodiments, post-traumatic stress biomarkers are proteins orprotein subunits (See, e.g., Table 1) the concentration of which in abiological sample (e.g., blood, saliva, urine, tissues, etc.) arealtered when compared to a control. In some embodiments, proteindetection and/or quantification reagents are provided. In embodiments inwhich a biomarker is a protein, polypeptide and/or peptide, detectionand/or quantification reagents may comprise antibodies or antibody-likereagents, aptamers, etc. that bind (e.g., specifically) to thebiomarker(s). In such embodiments, detection and/or quantification maybe achieved by, for example, an immunoassay, Western blot, enzyme-linkedimmunosorbent assay (ELISA), radioimmunoassay (RIA), fluorimetric assay,or other suitable assays known in the field.

In some embodiments, post-traumatic stress biomarkers are RNAs (e.g.,mRNA) (See, e.g., Table 1), the level of expression of which areindicative of post-traumatic stress states. In embodiments in which abiomarker is an RNA (e.g., mRNA), detection and/or quantificationreagents may comprise primers (e.g., for amplification, reversetranscription, etc.) or probes (e.g., detectably-labeled (e.g.,optically-labeled, fluorescently labeled, etc.) oligonucleotides) thatbind (e.g., specifically) to the biomarker. In such embodiments,detection and/or quantification may be achieved by, for example, RT-PCR,qPCR, dPCR, Northern blot analysis, an enzymatic cleavage assay (e.g.,INVADER, Hologic, Inc.; See e.g., U.S. Pat. Nos. 5,846,717, 6,090,543;6,001,567; 5,985,557; and 5,994,069; each of which is hereinincorporated by reference), a hybridization assay (e.g., TaqMan assay(Life Technologies; See e.g., U.S. Pat. Nos. 5,962,233 and 5,538,848,each of which is herein incorporated by reference), etc.

DEFINITIONS

As used herein, the term “subject” broadly refers to any animal,including but not limited to, human and non-human animals (e.g., dogs,cats, cows, horses, sheep, poultry, fish, crustaceans, etc.). As usedherein, the term “patient” typically refers to a subject that is beingtreated for a disease or condition.

As used herein, the term “sample” is used in its broadest sense. In onesense it can refer to biological samples obtained from animals(including humans) and encompass fluids, solids, tissues (e.g.,neurological tissue), and gases. Biological samples include bloodproducts (e.g., plasma and serum), saliva, urine, and the like. Theseexamples are not to be construed as limiting the sample types applicableto the present invention.

As used here, the term “antibody” includes monoclonal antibodies(including full length monoclonal antibodies), polyclonal antibodies,multispecific antibodies (e.g., bispecific antibodies), humanizedantibodies, and antibody fragments so long as they exhibit the desiredbiological activity. Antibodies can be conjugated to other molecules. Asused herein, the term “antibody fragments” refers to a portion of anintact antibody. Examples of antibody fragments include, but are notlimited to, linear antibodies; single-chain antibody molecules; Fc orFc′ peptides, Fab and Fab fragments, and multispecific antibodies formedfrom antibody fragments.

The terms “specific binding” or “specifically binding” when used inreference to the interaction of capture or detection reagent (e.g.,antibody, probe etc.) and a target or biomarker (e.g., protein, DNA,RNA, etc.) means that the interaction is dependent upon the presence ofa particular structure (i.e., the antigenic determinant or epitope; thenucleic acid sequence).

As used herein, the terms “non-specific binding” and “backgroundbinding” when used in reference to the interaction capture or detectionreagent (e.g., antibody probe etc.) and a target or biomarker (e.g.,protein, DNA, RNA, etc.) refer to an interaction that is not dependenton the presence of a particular structure or sequence.

As used herein, “a reagent that specifically detects expression levels”refers to reagents used to detect the expression of one or more genes(e.g., including but not limited to, the biomarkers herein). Examples ofsuitable reagents include but are not limited to, nucleic acid probescapable of specifically hybridizing to the gene of interest, aptamers,PCR primers capable of specifically amplifying the gene of interest, andantibodies capable of specifically binding to proteins expressed by thegene of interest.

As used herein, the term “nucleic acid detection assay” refers to anymethod of determining the nucleotide composition of a nucleic acid ofinterest. Nucleic acid detection assay include but are not limited to,DNA sequencing methods, probe hybridization methods, enzyme mismatchcleavage methods (e.g., Variagenics, U.S. Pat. Nos. 6,110,684,5,958,692, 5,851,770, herein incorporated by reference in theirentireties); polymerase chain reaction; branched hybridization methods(e.g., Chiron, U.S. Pat. Nos. 5,849,481, 5,710,264, 5,124,246, and5,624,802, herein incorporated by reference in their entireties);rolling circle replication (e.g., U.S. Pat. Nos. 6,210,884, 6,183,960and 6,235,502, herein incorporated by reference in their entireties);NASBA (e.g., U.S. Pat. No. 5,409,818, herein incorporated by referencein its entirety); molecular beacon technology (e.g., U.S. Pat. No.6,150,097, herein incorporated by reference in its entirety); E-sensortechnology (Motorola, U.S. Pat. Nos. 6,248,229, 6,221,583, 6,013,170,and 6,063,573, herein incorporated by reference in their entireties);cycling probe technology (e.g., U.S. Pat. Nos. 5,403,711, 5,011,769, and5,660,988, herein incorporated by reference in their entireties); DadeBehring signal amplification methods (e.g., U.S. Pat. Nos. 6,121,001,6,110,677, 5,914,230, 5,882,867, and 5,792,614, herein incorporated byreference in their entireties); ligase chain reaction (e.g., BarnayProc. Natl. Acad. Sci USA 88, 189-93 (1991)); and sandwich hybridizationmethods (e.g., U.S. Pat. No. 5,288,609, herein incorporated by referencein its entirety).

The term “primer” refers to an oligonucleotide, whether occurringnaturally as in a purified restriction digest or produced synthetically,that is capable of acting as a point of initiation of synthesis whenplaced under conditions in which synthesis of a primer extension productthat is complementary to a nucleic acid strand is induced, (e.g., in thepresence of nucleotides and an inducing agent such as a DNA polymeraseand at a suitable temperature and pH). The primer is preferably singlestranded for maximum efficiency in amplification, but may alternativelybe double stranded. If double stranded, the primer is first treated toseparate its strands before being used to prepare extension products.Preferably, the primer is an oligodeoxyribonucleotide. The primer mustbe sufficiently long to prime the synthesis of extension products in thepresence of the inducing agent. The exact lengths of the primers willdepend on many factors, including temperature, source of primer, and theuse of the method.

The term “probe” refers to an oligonucleotide (e.g., a sequence ofnucleotides), whether occurring naturally as in a purified restrictiondigest or produced synthetically, recombinantly, or by PCRamplification, that is capable of hybridizing to another oligonucleotideof interest. A probe may be single-stranded or double-stranded. Probesare useful in the detection, identification, and isolation of particulargene sequences (e.g., a “capture probe”). It is contemplated that anyprobe used in the present invention may, in some embodiments, be labeledwith any “reporter molecule,” so that is detectable in any detectionsystem, including, but not limited to enzyme (e.g., ELISA, as well asenzyme-based histochemical assays), fluorescent, radioactive, andluminescent systems. It is not intended that the present invention belimited to any particular detection system or label.

As used herein, a “diagnostic” test application includes the detectionor identification of a disease state or condition of a subject,determining the likelihood that a subject will contract a given diseaseor condition, determining the likelihood that a subject with a diseaseor condition will respond to therapy, determining the prognosis of asubject with a disease or condition (or its likely progression orregression), and determining the effect of a treatment on a subject witha disease or condition.

DETAILED DESCRIPTION

The present invention relates generally to the detection or diagnosis ofpost-traumatic stress states in a subject, and provides methods,reagents, and kits useful for this purpose. Provided herein arebiomarkers that are indicative of and/or diagnostic of PTSD. PTSDinvolves a failure in recovery and restitution of physiologicalhomeostasis, possibly resulting from individual vulnerability tostress-related biological processes; although the present invention isnot limited to any particular cause of PTSD and an understanding of thecause of PTSD is not necessary to practice the present invention. Incertain embodiments, the present invention provides a panel ofbiomarkers (e.g., blood biomarkers (e.g., genes that are over or underexpressed in a PTSD state), etc.) that indicate prolonged response tochronic stress. The panel has been identified in animal models, wherebythe prolonged post-stress changes in the blood of an animal that isknown to show depressive behavior, in comparison to other controlstrains, is an indication of posttraumatic stress states.

Experiments were conducted during development of embodiments of thepresent invention to generate a panel of PTSD markers using chronicstress and different animal strains. Strains of animals that are knownto show greater depressive-like behavior or vulnerability to stress, andcontrol strains were exposed to a chronic stress paradigm. Genome-widegene expression in the blood of animals exposed to no stress (NS) wascompared to expression in animals exposed to prolonged chronic restraintstress, either during the stress (chronic resistant stress (CRS)) or 10days post-stress (PCRS). In some embodiments, genes that have alteredexpression (e.g., increased or decreased) during stress and remainaltered 10 days after the chronic stress in a stress-reactive strain,but not in a “resilient” strain are determined to be predictors offailure in recovery or reinstitution of physiological homeostasis. Insome embodiments, genes that have altered expression (e.g., increased ordecreased) post-stress compared to both the no stress control and duringthe stress in a stress-reactive strain, but not in a “resilient” strainare determined to be predictors of failure in recovery or reinstitutionof physiological homeostasis.

Genome-wide gene expression in the amygdala and the hippocampus ofanimals exposed to no stress (NS) was also compared to expression inanimals exposed to prolonged chronic restraint stress, either during thestress (chronic resistant stress (CRS)) or 10 days post-stress (PCRS).In some embodiments, genes that have altered expression (e.g., increasedor decreased) during stress and remain altered 10 days after the chronicstress in a stress-reactive strain, but not in a “resilient” strain aredetermined to be predictors of failure in recovery or reinstitution ofphysiological homeostasis. In some embodiments, genes that have alteredexpression (e.g., increased or decreased) post-stress compared to boththe no stress control and during the stress in a stress-reactive strain,but not in a “resilient” strain are determined to be predictors offailure in recovery or reinstitution of physiological homeostasis. Thosegenes that share significant expression differences between these stressstates in the blood and in the amygdala or hippocampus are markers ofpost traumatic stress states.

In some embodiments, the present invention provides biological markersindicative of a post-traumatic stress state in a subject. In someembodiments, the presence of such biomarkers (e.g., elevated or reducedexpression of biomarker genes) is indicative of and/or diagnostic of aprolonged response to stress (e.g., chronic stress). In someembodiments, biological markers are indicative of and/or diagnostic ofPTSD. In some embodiments, biological markers are blood biomarkers. Insome embodiments, the present invention provides one or more biomarkers,or a panel of biological markers, that can be identified from tissue orblood or other sample types. In some embodiments, these biologicalmarkers show increased or decreased levels of gene-specific RNA insubjects with current symptoms (e.g., PTSD symptoms) compared to thoseof controls (e.g., a subject who has experienced chronic stress withoutdeveloping PTSD, a subject not exposed to chronic stress, etc.). In someembodiments, these biological markers show increased or decreased levelsof protein expressed from these genes in subjects with current symptoms(e.g., PTSD symptoms) compared to those of controls (e.g., a subject whohas experienced chronic stress without developing PTSD, a subject notexposed to chronic stress, etc.).

In some embodiments, a subject to be tested by the methods and reagentsdescribed herein exhibits one or more symptoms of post-traumatic stressand/or has one or more risk factors for PTSD. Symptoms of PTSD include,for example: intrusive memories (e.g., recurrent, unwanted distressingmemories of the traumatic event; reliving the traumatic event as if itwere happening again (flashbacks); upsetting dreams about the traumaticevent; severe emotional distress or physical reactions to something thatreminds the subject of the event, etc.), avoidance (e.g., trying toavoid thinking or talking about the traumatic event; avoiding places,activities or people that remind the subject of the traumatic event;etc.), negative changes in thinking and mood (e.g., negative feelingsabout self or others; inability to experience positive emotions; feelingemotionally numb; lack of interest in activities the subject onceenjoyed; hopelessness about the future; memory problems, including notremembering important aspects of the traumatic event; difficultymaintaining close relationships; etc.), changes in emotional reactions(e.g., irritability, angry outbursts or aggressive behavior; alwaysbeing on guard for danger; overwhelming guilt or shame; self-destructivebehavior, such as drinking too much or driving too fast; troubleconcentrating; trouble sleeping; being easily startled or frightened;etc.), etc. Risk factors of PTSD include, for example: experiencingintense or long-lasting trauma; having experienced other trauma earlierin life, including childhood abuse or neglect; having a job thatincreases your risk of being exposed to traumatic events, such asmilitary personnel and first responders; having other mental healthproblems, such as anxiety or depression; lacking a good support systemof family and friends; having biological relatives with mental healthproblems, including PTSD or depression; etc. In some embodiments, priorto, concurrent with, and/or following testing a subject for PTSDbiomarkers according to embodiments described herein, a subject isevaluated for symptoms and/or risk factors of post-traumatic stress.

In some embodiments, biomarkers provide confirmation that a subject'ssymptoms are the result of PTSD. In other embodiments, biomarkerspredict whether a subject who has experienced chronic stress willdevelop PTSD at a later time. In some embodiments, biomarkers predictwhether a subject will develop PTSD after experiencing a traumaticevent. In some embodiments, biomarkers allow diagnosis of PTSD in asubject not actively experiencing symptoms or unable to communicate suchsymptoms. In some embodiments, biomarkers differentiate between asubject experiencing symptoms caused by current chronic stress and thosecaused by PTSD.

The present invention relates to the biomarkers of Table 1 and/or theuse thereof in detecting, characterizing, identifying, and/or diagnosingprolonged responses to chronic stress in a subject. Experiments wereconducted during development of embodiments of the present invention toidentify biomarkers that are indicative and/or diagnostic of PTSD. Insome embodiments, biomarkers of column 1 of Table 1 find use indiagnosis and/or characterization of PTSD. In some embodiments,biomarkers of column 1 of Table 1, when altered in a subjectexperiencing stress or following stress (e.g., compared to control,compared to a threshold level, etc.), are indicative of PTSD. In someembodiments, biomarkers of column 2 of Table 1 find use in diagnosisand/or characterization of PTSD. In some embodiments, biomarkers ofcolumn 2 of Table 1, when altered in a subject post-stress but notduring stress (e.g., compared to control, compared to a threshold level,etc.), are indicative of PTSD. In some embodiments, biomarkers of column3 of Table 1 find use in diagnosis and/or characterization of PTSD. Insome embodiments, biomarkers of column 3 of Table 1, when altered in asubject post-stress but not during stress (e.g., compared to control,compared to a threshold level, etc.), are indicative of PTSD. In someembodiments, biomarkers of column 4 of Table 1 find use in diagnosisand/or characterization of PTSD. In some embodiments, biomarkers ofcolumn 4 of Table 1, when altered in a subject post-stress but notduring stress (e.g., compared to control, compared to a threshold level,etc.), are indicative of PTSD. In some embodiments, biomarkers of column5 of Table 1 find use in diagnosis and/or characterization of PTSD. Insome embodiments, biomarkers of column 5 of Table 1, when altered in asubject post-stress but not during stress (e.g., compared to control,compared to a threshold level, etc.), are indicative of PTSD. In someembodiments, biomarkers of column 6 of Table 1 find use in diagnosisand/or characterization of PTSD. In some embodiments, biomarkers ofcolumn 6 of Table 1, when altered in a subject post-stress but notduring stress (e.g., compared to control, compared to a threshold level,etc.), are indicative of PTSD. In some embodiments, a panel ofbiomarkers for characterization and/or diagnosis of PTSD comprisesbiomarkers from one or more columns of Table 1 (e.g., a single column,two columns, three columns, four columns, five columns, six columns). Insome embodiments, altered expression (e.g., as evidenced by altered mRNAlevel, protein level, etc. compared to a threshold or control value).

In some embodiments, the present invention provides one or morebiomarkers listed in Table 1 or a particular column or set of columnstherein (e.g., column 6, columns 5 and 6, etc.). In some embodiments,the present invention provides a panel of biomarkers comprising aplurality (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10 . . . 15 . . . 20 . . . 30 .. . 40, or more) of biomarkers listed in Table 1 (or a particular columnor set of columns therein (e.g., column 6, columns 5 and 6, etc.). Insome embodiments the present invention provides a panel of reagents fordetecting mRNAs or encoded proteins comprising one or more genes fromTable 1 (or a particular column or set of columns therein (e.g., column6, columns 5 and 6, etc.). In some embodiments the present inventionprovides a panel of reagents for detecting mRNAs or encoded proteinsconsisting of one or more genes from Table 1 (or a particular column orset of columns therein (e.g., column 6, columns 5 and 6, etc.). In someembodiments, a panel comprises one or more reagents for detecting mRNAsor encoded proteins from Table 1 and one or more additional genes. Insome embodiments, the present invention provides a set of genes whosemRNA levels differ in (e.g., in the blood of) subjects showing higherand lower level of prolonged response to stress (e.g., PTSD). In someembodiments, the present invention provides a set of genes whose proteinlevels differ in (e.g., in the blood of) subjects showing higher andlower level of prolonged response to stress (e.g., PTSD). In someembodiments, the present invention provides biological markers that arecommon between those expressed in the blood and those expressed in thebrain regions of animals, showing higher and lower level of prolongedresponse to stress (e.g., PTSD). In some embodiments of the presentinvention, the expression of one or more such genes are used to diagnoseor suggest a risk of PTSD from human sample (e.g., blood sample). Insome embodiments, the presence of a gene or panel of genes (or alteredtranscript levels of such genes) that correlates with PTSD (e.g., isindicative of PTSD, is diagnostic of PTSD) allows a treating physicianto take any number of courses of action, including, but not limited to,further diagnostic assessment, selection of appropriate treatment (e.g.,pharmacological, nutritional, counseling, and the like), increased ordecreased monitoring, etc. In some embodiments, changes in expression ofa gene or panel of genes that correlates with PTSD (e.g., is indicativeof PTSD, is diagnostic of PTSD) allows a treating physician to take anynumber of courses of action, including, but not limited to, furtherdiagnostic assessment, selection of appropriate treatment (e.g.,pharmaceutical, nutritional, counseling, and the like), increased ordecreased monitoring, etc.

In some embodiments the present invention provides a method fordetecting or assessing the risk of prolonged response to chronic stress(e.g., PTSD) in a subject. In some embodiments the present inventionprovides a method for diagnosing PTSD in a subject. In some embodiments,the biomarkers provided herein are used in conjunction with otherevidence of PTSD (e.g., symptoms, risk factors, etc.) in making adiagnosis. In some embodiments, the biomarkers provided herein are usedin the absence of other evidence of PTSD (e.g., symptoms) in making adiagnosis.

In some embodiments the present invention provides methods forcharacterizing the level of gene expression of a panel of genescomprising detecting the amount of mRNA of a panel of genes of one ormore of the genes listed in Table 1 (or a particular column or set ofcolumns therein (e.g., column 6, columns 5 and 6, etc.). In someembodiments, the panel comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20 . . . 30 . . . 40, or more genes. In someembodiments the present invention provides methods comprising the stepof exposing a sample to nucleic acid probes complementary to the mRNA ofa panel of genes selected from the genes listed in Table 1 (or aparticular column or set of columns therein (e.g., column 6, columns 5and 6, etc.). In some embodiments the methods employ a nucleic aciddetection technique (e.g., microarray analysis, reverse transcriptasePCR, quantitative reverse transcriptase PCR, and hybridizationanalysis).

In some embodiments the present invention provides methods forcharacterizing the level of gene expression of a panel of genes bydetecting the amount of protein (e.g., in the blood) corresponding toone or more of the genes listed in Table 1. In some embodiments, a panelcomprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20 . . . 30 . . . 40, etc. genes. In some embodiments the presentinvention provides methods comprising the step of exposing a sample toantibodies (or antibody fragments, or aptamers, etc.) for the proteinscorresponding to one or more of the genes listed in Table 1. In someembodiments, detecting a change in the expression of one or more of thegenes listed in Table 1 comprises exposing a sample (e.g., blood sample)to antibodies (or antibody fragments, or aptamers, etc.) specific to thebiomarkers and detecting binding to the biomarkers. In some embodimentsthe present invention provides a method for detecting prolonged responseto chronic stress (e.g., PTSD) in a human subject.

In some embodiments, biomarkers for use in a panel and/or in an assayfor characterization/diagnosis of PTSD are selected from SERPINB1,LILRB3, and GLRX (e.g., one or more of those markers alone or incombination with other markers from Table 1 or genes known in thefield). In some embodiments, altered expression (e.g., consistent withexperiments conducted during development of embodiments of the presentinvention) of one or more of SERPINB1, LILRB3, and GLRX is indicativeand/or diagnostic of prolonged stress response (e.g., PTSD).

In some embodiments, biomarkers for use in a panel and/or in an assayfor characterization/diagnosis of PTSD are selected from IFI27, FUOM,HSPA8, IGK, LCMT1, THYN1, SEC14L2, SLC16A3, SERINC2, TRPM6, and XKRX(e.g., one or more of those markers alone or in combination with othermarkers from Table 1 (e.g., one or more of SERPINB1, LILRB3, and GLRX)or genes known in the field). In some embodiments, the panel furthercomprises one or more of CYP21A1, ADN, DGAT2, PROK2, TNFRSF1A andELOVL5. In some embodiments, altered expression (e.g., consistent withexperiments conducted during development of embodiments of the presentinvention) of one or more of IFI27, FUOM, HSPA8, IGK, LCMT1, THYN1,SEC14L2, SLC16A3, SERINC2, TRPM6, and XKRX is indicative and/ordiagnostic of prolonged stress response (e.g., PTSD). In someembodiments, altered expression (e.g., consistent with experimentsconducted during development of embodiments of the present invention) ofone or more of CYP21A1, ADN, DGAT2, PROK2, TNFRSF1A and ELOVL5 isindicative and/or diagnostic of prolonged stress response (e.g., PTSD).

In some embodiments the present invention relates to gene expressionprofiles (e.g., increases and/or decrease in the expression of multiplegenes) that correlate with prolonged response to chronic stress (e.g.,PTSD), and uses thereof. In some embodiments, a panel of two or moregenes is analyzed (e.g., 2 genes . . . 4 genes . . . 6 genes . . . 8genes . . . 10 genes . . . 15 genes . . . 20 genes . . . 30 genes, ormore.). In some embodiments, detection and/or quantification reagents(e.g., oligonucleotide probes) are provided that have specificity forgenes associated prolonged response to chronic stress (e.g., PTSD) (See,e.g., genes identified in Table 1).

In some embodiments, the present invention provides a panel ofbiomarkers for the detection, characterization, and/or diagnosis of avariety of diseases and/or conditions (e.g., psychiatric conditions,mental disease, genetic conditions, physical diseases, etc.), one ofwhich is PTSD. In certain embodiments, a panel comprises multiplebiomarkers from Table 1 (e.g., column 6, column 5, etc.) in addition tobiomarkers for other diseases or conditions (e.g., depression, anxiety,etc.). In particular embodiments, testing a subject (e.g., a bloodsample from a subject) for such a panel allows diagnosis of PTSD inaddition to other diseases, conditions, or disorders. In someembodiments, all the biomarkers on the panel are provided for adiagnostic or other medical purpose.

It is contemplated that a test sample (e.g., containing isolated and/orpurified biomarker protein and/or RNA, containing test reagents, etc.)is prepared from biological (e.g., saliva, blood, etc.) samples fromsubject (e.g., with PTSD), and the test samples are applied to thepanel. It is contemplated that the differential hybridization of thepatient samples relative to the control samples provides an expressionsignature of PTSD. In some embodiments, gene expression from a testsample is compared with a prior sample from the same patient to monitorchanges over time. In some embodiments, gene expression from a testsample is compared with a sample from the patient under a treatmentregimen (e.g., pharmaceutical therapy) to test or monitor the effect ofthe therapy. In some embodiments, gene expression from a test sample iscompared to gene expression from a negative control sample (e.g., asubject known to not have PTSD). In some embodiments, gene expressionlevels from a test sample are compared to predetermined threshold levelsidentified (e.g., based on population averages for patients with similarage, gender, metabolism, etc.) as “normal” for individuals without PTSD.In some embodiments, an increase or decrease of greater than 1.1-fold(e.g., 1.2-fold, 1.5-fold, 2-fold, 3-fold, 5-fold, 10-fold, or higher)compared to “normal” levels or any increase over a normal level orthreshold level is indicative of and/or diagnostic for PTSD. In someembodiments, separate indicative and diagnostic thresholds areestablished.

The level of biomarker(s) present in a sample may be assessed on anabsolute basis or a relative basis. When assessed on a relative basis,comparison may be made to controls including but not limited to ahistorical sample from the same patient (e.g., serial samples,longitudinal samples); level(s) found in a patient or population ofpatients absent of disease or disorder; a threshold value; andacceptable range; etc.

In some embodiments, provided herein are DNA-, RNA- and protein-baseddiagnostic methods that either directly or indirectly detect thebiomarkers described herein. The present invention also providescompositions, reagents, and kits for such diagnostic purposes. Thediagnostic methods described herein may be qualitative or quantitative.Quantitative diagnostic methods may be used, for example, to compare adetected biomarker level to a cutoff or threshold level. Whereapplicable, qualitative or quantitative diagnostic methods may alsoinclude amplification of target, signal or intermediary.

In some embodiments, biomarkers are detected at the nucleic acid (e.g.,RNA) level. For example, the amount of biomarker RNA (e.g., mRNA)present in a sample is determined (e.g., to determine the level ofbiomarker expression). Biomarker nucleic acid (e.g., RNA, amplifiedcDNA, etc.) may be detected/quantified using a variety of nucleic acidtechniques known to those of ordinary skill in the art, including butnot limited to nucleic acid sequencing, nucleic acid hybridization, andnucleic acid amplification.

In some embodiments, a microarray is used to detect nucleic acidbiomarkers (e.g., those of Table 1). Different kinds of biologicalassays are called microarrays including, but not limited to: DNAmicroarrays (e.g., cDNA microarrays and oligonucleotide microarrays);protein microarrays; tissue microarrays; transfection or cellmicroarrays; chemical compound microarrays; and, antibody microarrays. ADNA microarray, commonly known as gene chip, DNA chip, or biochip, istypically a collection of microscopic DNA spots attached to a solidsurface (e.g., glass, plastic or silicon chip) forming an array for thepurpose of expression profiling or monitoring expression levels forthousands of genes simultaneously. The affixed DNA segments are known asprobes, thousands of which can be used in a single DNA microarray.Microarrays can be used to identify disease genes by comparing geneexpression in disease and normal cells. Microarrays can be fabricatedusing a variety of technologies, including but not limiting: printingwith fine-pointed pins onto glass slides; photolithography usingpre-made masks; photolithography using dynamic micromirror devices; inkjet printing; or, electrochemistry on microelectrode arrays.

Southern and Northern blotting is used to detect specific DNA or RNAsequences, respectively. DNA or RNA extracted from a sample isfragmented, electrophoretically separated on a matrix gel, andtransferred to a membrane filter. The filter bound DNA or RNA is subjectto hybridization with a labeled probe complementary to the sequence ofinterest. Hybridized probe bound to the filter is detected. A variant ofthe procedure is the reverse Northern blot, in which the substratenucleic acid that is affixed to the membrane is a collection of isolatedDNA fragments and the probe is RNA extracted from a tissue and labeled.

Genomic DNA and mRNA may be amplified prior to or simultaneous withdetection. Illustrative non-limiting examples of nucleic acidamplification techniques include, but are not limited to, polymerasechain reaction (PCR), reverse transcription polymerase chain reaction(RT-PCR), transcription-mediated amplification (TMA), ligase chainreaction (LCR), strand displacement amplification (SDA), and nucleicacid sequence based amplification (NASBA). Those of ordinary skill inthe art will recognize that certain amplification techniques (e.g., PCR)require that RNA be reversed transcribed to DNA prior to amplification(e.g., RT-PCR), whereas other amplification techniques directly amplifyRNA (e.g., TMA and NASBA).

The polymerase chain reaction (U.S. Pat. Nos. 4,683,195, 4,683,202,4,800,159 and 4,965,188, each of which is herein incorporated byreference in its entirety), commonly referred to as PCR, uses multiplecycles of denaturation, annealing of primer pairs to opposite strands,and primer extension to exponentially increase copy numbers of a targetnucleic acid sequence. In a variation called RT-PCR, reversetranscriptase (RT) is used to make a complementary DNA (cDNA) from mRNA,and the cDNA is then amplified by PCR to produce multiple copies of DNA.In some embodiments, PCR is digital PCR, see, e.g., Vogelstein, B., &Kinzler, K. W. (1999) “Digital PCR” Proc. Natl. Acad. Sci. USA96:9236-9241; herein incorporated by reference in its entirety. Forother various permutations of PCR see, e.g., U.S. Pat. Nos. 4,683,195,4,683,202 and 4,800,159; Mullis et al., Meth. Enzymol. 155: 335 (1987);and, Murakawa et al., DNA 7: 287 (1988), each of which is hereinincorporated by reference in its entirety.

Transcription mediated amplification (U.S. Pat. Nos. 5,480,784 and5,399,491, each of which is herein incorporated by reference in itsentirety), commonly referred to as TMA, synthesizes multiple copies of atarget nucleic acid sequence autocatalytically under conditions ofsubstantially constant temperature, ionic strength, and pH in whichmultiple RNA copies of the target sequence autocatalytically generateadditional copies. See, e.g., U.S. Pat. Nos. 5,399,491 and 5,824,518,each of which is herein incorporated by reference in its entirety. In avariation described in U.S. Publ. No. 20060046265 (herein incorporatedby reference in its entirety), TMA optionally incorporates the use ofblocking moieties, terminating moieties, and other modifying moieties toimprove TMA process sensitivity and accuracy.

The ligase chain reaction (Weiss, R., Science 254: 1292 (1991), hereinincorporated by reference in its entirety), commonly referred to as LCR,uses two sets of complementary DNA oligonucleotides that hybridize toadjacent regions of the target nucleic acid. The DNA oligonucleotidesare covalently linked by a DNA ligase in repeated cycles of thermaldenaturation, hybridization and ligation to produce a detectabledouble-stranded ligated oligonucleotide product.

Strand displacement amplification (Walker, G. et al., Proc. Natl. Acad.Sci. USA 89: 392-396 (1992); U.S. Pat. Nos. 5,270,184 and 5,455,166,each of which is herein incorporated by reference in its entirety),commonly referred to as SDA, uses cycles of annealing pairs of primersequences to opposite strands of a target sequence, primer extension inthe presence of a dNTPαS to produce a duplex hemiphosphorothioatedprimer extension product, endonuclease-mediated nicking of ahemimodified restriction endonuclease recognition site, andpolymerase-mediated primer extension from the 3′ end of the nick todisplace an existing strand and produce a strand for the next round ofprimer annealing, nicking and strand displacement, resulting ingeometric amplification of product. Thermophilic SDA (tSDA) usesthermophilic endonucleases and polymerases at higher temperatures inessentially the same method (EP Pat. No. 0 684 315).

Other amplification methods include, for example: nucleic acid sequencebased amplification (U.S. Pat. No. 5,130,238, herein incorporated byreference in its entirety), commonly referred to as NASBA; one that usesan RNA replicase to amplify the probe molecule itself (Lizardi et al.,BioTechnol. 6: 1197 (1988), herein incorporated by reference in itsentirety), commonly referred to as Qβ replicase; a transcription basedamplification method (Kwoh et al., Proc. Natl. Acad. Sci. USA 86:1173(1989)); and, self-sustained sequence replication (Guatelli et al.,Proc. Natl. Acad. Sci. USA 87: 1874 (1990), each of which is hereinincorporated by reference in its entirety). For further discussion ofknown amplification methods see Persing, David H., “In Vitro NucleicAcid Amplification Techniques” in Diagnostic Medical Microbiology:Principles and Applications (Persing et al., Eds.), pp. 51-87 (AmericanSociety for Microbiology, Washington, DC (1993)).

Non-amplified or amplified nucleic acids can be detected by anyconventional means. For example, in some embodiments, nucleic acids aredetected by hybridization with a detectably labeled probe andmeasurement of the resulting hybrids. Illustrative non-limiting examplesof detection methods are described below.

One illustrative detection method, the Hybridization Protection Assay(HPA) involves hybridizing a chemiluminescent oligonucleotide probe(e.g., an acridinium ester-labeled (AE) probe) to the target sequence,selectively hydrolyzing the chemiluminescent label present onunhybridized probe, and measuring the chemiluminescence produced fromthe remaining probe in a luminometer. See, e.g., U.S. Pat. No. 5,283,174and Norman C. Nelson et al., Nonisotopic Probing, Blotting, andSequencing, ch. 17 (Larry J. Kricka ed., 2d ed. 1995, each of which isherein incorporated by reference in its entirety).

Another illustrative detection method provides for quantitativeevaluation of the amplification process in real-time. Evaluation of anamplification process in “real-time” involves determining the amount ofamplicon in the reaction mixture either continuously or periodicallyduring the amplification reaction, and using the determined values tocalculate the amount of target sequence initially present in the sample.A variety of methods for determining the amount of initial targetsequence present in a sample based on real-time amplification are wellknown in the art. These include methods disclosed in U.S. Pat. Nos.6,303,305 and 6,541,205, each of which is herein incorporated byreference in its entirety. Another method for determining the quantityof target sequence initially present in a sample, but which is not basedon a real-time amplification, is disclosed in U.S. Pat. No. 5,710,029,herein incorporated by reference in its entirety.

Amplification products may be detected in real-time through the use ofvarious self-hybridizing probes, most of which have a stem-loopstructure. Such self-hybridizing probes are labeled so that they emitdifferently detectable signals, depending on whether the probes are in aself-hybridized state or an altered state through hybridization to atarget sequence. By way of non-limiting example, “molecular torches” area type of self-hybridizing probe that includes distinct regions ofself-complementarity (referred to as “the target binding domain” and“the target closing domain”) which are connected by a joining region(e.g., non-nucleotide linker) and which hybridize to each other underpredetermined hybridization assay conditions. In a preferred embodiment,molecular torches contain single-stranded base regions in the targetbinding domain that are from 1 to about 20 bases in length and areaccessible for hybridization to a target sequence present in anamplification reaction under strand displacement conditions. Understrand displacement conditions, hybridization of the two complementaryregions, which may be fully or partially complementary, of the moleculartorch is favored, except in the presence of the target sequence, whichwill bind to the single-stranded region present in the target bindingdomain and displace all or a portion of the target closing domain. Thetarget binding domain and the target closing domain of a molecular torchinclude a detectable label or a pair of interacting labels (e.g.,luminescent/quencher) positioned so that a different signal is producedwhen the molecular torch is self-hybridized than when the moleculartorch is hybridized to the target sequence, thereby permitting detectionof probe:target duplexes in a test sample in the presence ofunhybridized molecular torches. Molecular torches and a variety of typesof interacting label pairs are disclosed in U.S. Pat. No. 6,534,274,herein incorporated by reference in its entirety.

Another example of a detection probe having self-complementarity is a“molecular beacon.” Molecular beacons include nucleic acid moleculeshaving a target complementary sequence, an affinity pair (or nucleicacid arms) holding the probe in a closed conformation in the absence ofa target sequence present in an amplification reaction, and a label pairthat interacts when the probe is in a closed conformation. Hybridizationof the target sequence and the target complementary sequence separatesthe members of the affinity pair, thereby shifting the probe to an openconformation. The shift to the open conformation is detectable due toreduced interaction of the label pair, which may be, for example, afluorophore and a quencher (e.g., DABCYL and EDANS). Molecular beaconsare disclosed in U.S. Pat. Nos. 5,925,517 and 6,150,097, hereinincorporated by reference in its entirety.

Other self-hybridizing probes are well known to those of ordinary skillin the art. By way of non-limiting example, probe binding pairs havinginteracting labels, such as those disclosed in U.S. Pat. No. 5,928,862(herein incorporated by reference in its entirety) might be adapted foruse in the present invention. Probe systems used to detect singlenucleotide polymorphisms (SNPs) might also be utilized in the presentinvention. Additional detection systems include “molecular switches,” asdisclosed in U.S. Publ. No. 20050042638, herein incorporated byreference in its entirety. Other probes, such as those comprisingintercalating dyes and/or fluorochromes, are also useful for detectionof amplification products in the present invention. See, e.g., U.S. Pat.No. 5,814,447 (herein incorporated by reference in its entirety).

In some embodiments, quantitative PCR (qPCR) is utilized, e.g., usingSYBR Green dye on an Applied Biosystems 7300 Real Time PCR systemessentially as described (Chinnaiyan et al., Cancer Res 65, 3328 (2005);Rubin et al., Cancer Res 64, 3814 (2004); herein incorporated byreference in its entirety).

In some embodiments, nucleic acid from a sample is sequenced (e.g., inorder to detect biomarkers). Nucleic acid molecules may be sequenceanalyzed by any number of techniques. The analysis may identify thesequence of all or a part of a nucleic acid. Illustrative non-limitingexamples of nucleic acid sequencing techniques include, but are notlimited to, chain terminator (Sanger) sequencing and dye terminatorsequencing, as well as “next generation” sequencing techniques. Those ofordinary skill in the art will recognize that because RNA is less stablein the cell and more prone to nuclease attack, experimentally RNA isusually, although not necessarily, reverse transcribed to DNA beforesequencing.

A number of DNA sequencing techniques are known in the art, includingfluorescence-based sequencing methodologies (See, e.g., Birren et al.,Genome Analysis: Analyzing DNA, 1, Cold Spring Harbor, N.Y.; hereinincorporated by reference in its entirety). In some embodiments,automated sequencing techniques understood in that art are utilized. Insome embodiments, the systems, devices, and methods employ parallelsequencing of partitioned amplicons (PCT Publication No: WO2006084132 toKevin McKernan et al., herein incorporated by reference in itsentirety). In some embodiments, DNA sequencing is achieved by paralleloligonucleotide extension (See, e.g., U.S. Pat. No. 5,750,341 toMacevicz et al., and U.S. Pat. No. 6,306,597 to Macevicz et al., both ofwhich are herein incorporated by reference in their entireties).Additional examples of sequencing techniques include the Church polonytechnology (Mitra et al., 2003, Analytical Biochemistry 320, 55-65;Shendure et al., 2005 Science 309, 1728-1732; U.S. Pat. Nos. 6,432,360,6,485,944, 6,511,803; herein incorporated by reference in theirentireties) the 454 picotiter pyrosequencing technology (Margulies etal., 2005 Nature 437, 376-380; US 20050130173; herein incorporated byreference in their entireties), the Solexa single base additiontechnology (Bennett et al., 2005, Pharmacogenomics, 6, 373-382; U.S.Pat. Nos. 6,787,308; 6,833,246; herein incorporated by reference intheir entireties), the Lynx massively parallel signature sequencingtechnology (Brenner et al. (2000). Nat. Biotechnol. 18:630-634; U.S.Pat. Nos. 5,695,934; 5,714,330; herein incorporated by reference intheir entireties) and the Adessi PCR colony technology (Adessi et al.(2000). Nucleic Acid Res. 28, E87; WO 00018957; herein incorporated byreference in its entirety).

A set of methods referred to as “next-generation sequencing” techniqueshave emerged as alternatives to Sanger and dye-terminator sequencingmethods (Voelkerding et al., Clinical Chem., 55: 641-658, 2009; MacLeanet al., Nature Rev. Microbiol., 7: 287-296; each herein incorporated byreference in their entirety). Next-generation sequencing (NGS) methodsshare the common feature of massively parallel, high-throughputstrategies, with the goal of lower costs in comparison to oldersequencing methods. NGS methods can be broadly divided into those thatrequire template amplification and those that do not.Amplification-requiring methods include pyrosequencing commercialized byRoche as the 454 technology platforms (e.g., GS 20 and GS FLX), theSolexa platform commercialized by Illumina, and the SupportedOligonucleotide Ligation and Detection (SOLiD) platform commercializedby Applied Biosystems. Non-amplification approaches, also known assingle-molecule sequencing, are exemplified by the HeliScope platformcommercialized by Helicos BioSciences, Pacific Biosciences (PAC BIO RSII) and other platforms commercialized.

In some embodiments, provided herein are methods for isolating DNA orRNA from a biological sample. Methods may comprise steps of homogenizinga sample in a suitable buffer, removal of contaminants and/or assayinhibitors adding a target capture reagent (e.g., a magnetic bead towhich is linked an oligonucleotide complementary to the target),incubated under conditions that promote the association (e.g., byhybridization) of the target with the capture reagent to produce atarget:capture reagent complex, incubating the target:capture complexunder target-release conditions. In some embodiments, multiple biomarkertargets are isolated in each round of isolation by adding multipletarget capture reagents (e.g., specific to the desired biomarkers) tothe solution. For example, multiple target capture reagents, eachcomprising an oligonucleotide specific for a different biomarker targetcan be added to the sample for isolation of multiple targets. It iscontemplated that the methods encompass multiple experimental designsthat vary both in the number of capture steps and in the number oftargets captured in each capture step. In some embodiments, capturereagents are molecules, moieties, substances, or compositions thatpreferentially (e.g., specifically and selectively) interact with aparticular biomarker sought to be isolated, purified, detected, and/orquantified. Any capture reagent having desired binding affinity and/orspecificity to the analyte target can be used in the present technology.For example, the capture reagent can be a macromolecule such as apeptide, a protein (e.g., an antibody or receptor), an oligonucleotide,a nucleic acid, (e.g., nucleic acids capable of hybridizing with thetarget nucleic acids), vitamins, oligosaccharides, carbohydrates,lipids, or small molecules, or a complex thereof. As illustrative andnon-limiting examples, an avidin target capture reagent may be used toisolate and purify targets comprising a biotin moiety, an antibody maybe used to isolate and purify targets comprising the appropriate antigenor epitope, and an oligonucleotide may be used to isolate and purify acomplementary oligonucleotide.

Any nucleic acids, including single-stranded and double-stranded nucleicacids, that are capable of binding, or specifically binding, to thetarget can be used as the capture reagent. Examples of such nucleicacids include DNA, RNA, aptamers, peptide nucleic acids, and othermodifications to the sugar, phosphate, or nucleoside base. Thus, thereare many strategies for capturing a target and accordingly many types ofcapture reagents are known to those in the art.

In addition, target capture reagents comprise a functionality tolocalize, concentrate, aggregate, etc. the capture reagent and thusprovide a way to isolate and purify the target biomarker when captured(e.g., bound, hybridized, etc.) to the capture reagent (e.g., when atarget:capture reagent complex is formed). For example, in someembodiments the portion of the target capture reagent that interactswith the target (e.g., the oligonucleotide) is linked to a solid support(e.g., a bead, surface, resin, column, and the like) that allowsmanipulation by the user on a macroscopic scale. Often, the solidsupport allows the use of a mechanical means to isolate and purify thetarget:capture reagent complex from a heterogeneous solution. Forexample, when linked to a bead, separation is achieved by removing thebead from the heterogeneous solution, e.g., by physical movement. Inembodiments in which the bead is magnetic or paramagnetic, a magneticfield is used to achieve physical separation of the capture reagent (andthus the target) from the heterogeneous solution. Magnetic beads used toisolate targets are described in the art, e.g., as described in EuropeanPatent Application No. 87309308, incorporated herein in its entirety forall purposes.

In some embodiments, a computer-based analysis program is used totranslate the raw data generated by the detection assay (e.g., thepresence, absence, or amount of expression a panel of genes) into dataof predictive value for a clinician (e.g., a risk score, a qualitativedescription, etc.). In some embodiments, data analysis produces a PTSDrisk or likelihood score. In some embodiments, data analysis produces aPTSD diagnosis. In some embodiments, computer analysis combines the datafrom numerous biomarkers into a single score or value that is predictiveand/or diagnostic for PTSD.

In some embodiments, a clinician accesses the data and/or analysisthereof using any suitable means. Thus, in some preferred embodiments,the present invention provides the further benefit that the clinician,who is not likely to be trained in genetics or molecular biology, neednot understand the raw data. The data is presented directly to theclinician in its most useful form. The clinician is then able toimmediately utilize the information in order to optimize the care of thesubject.

The present invention contemplates any method capable of receiving,processing, and transmitting the information to and from laboratoriesconducting the assays, information providers, medical personal, andsubjects. For example, in some embodiments of the present invention, asample (e.g., a biopsy or a blood, serum or saliva sample) is obtainedfrom a subject and submitted to a profiling service (e.g., clinical labat a medical facility, third-party testing service, genomic profilingbusiness, etc.), located in any part of the world (e.g., in a countrydifferent than the country where the subject resides or where theinformation is ultimately used) to generate raw data. Where the samplecomprises a tissue or other biological sample, the subject may visit amedical center to have the sample obtained and sent to the profilingcenter, or subjects may collect the sample themselves (e.g., a blood orsaliva sample, a urine sample, etc.) and directly send it to a profilingcenter. Where the sample also comprises previously determined biologicalinformation, the information may be directly sent to the profilingservice by the subject (e.g., an information card containing theinformation may be scanned by a computer and the data transmitted to acomputer of the profiling center using an electronic communicationsystems). Once received by the profiling service, the sample isprocessed and a profile is produced (e.g., expression data), specificfor the diagnostic or prognostic information desired for the subject.

In some embodiments, profile data is prepared in a format suitable forinterpretation by a treating clinician and/or the test subject. Forexample, rather than providing raw expression data, the prepared formatmay represent a diagnosis or risk assessment (e.g., likelihood ofsubject having PTSD) for the subject. Recommendations for particulartreatment options may also be provided. The data may be displayed to theclinician by any suitable method. For example, in some embodiments, theprofiling service generates a report that can be printed for theclinician (e.g., at the point of care) or displayed to the clinician ona computer monitor.

In some embodiments, a report is generated (e.g., by a clinician, by atesting center, by a computer or other automated analysis system, etc.).A report may contain test results, diagnoses (e.g., PTSD, highlikelihood of PTSD, sever PTSD, etc.), and/or treatment recommendations(e.g., psychoanalysis, psychotherapy, pharmaceutical treatment,observation, etc.).

In some embodiments, the information is first analyzed at the point ofcare or at a regional facility. The raw data is then sent to a centralprocessing facility for further analysis and/or to convert the raw datato information useful for a clinician or patient. The central processingfacility provides the advantage of privacy (all data is stored in acentral facility with uniform security protocols), speed, and uniformityof data analysis. The central processing facility can then control thefate of the data following treatment of the subject. For example, usingan electronic communication system, the central facility can providedata to the clinician, the subject, or researchers.

In some embodiments, the subject is able to directly access the datausing the electronic communication system. The subject may choosefurther intervention, treatment, and/or counseling based on the results.In some embodiments, the data is used for research use. For example, thedata may be used to further optimize the inclusion or elimination ofmarkers as more or less useful indicators of PTSD (e.g., in a particularpopulation (e.g., children, adolescents, adults, males, females, etc.).

Compositions for use in the diagnostic methods of the present inventioninclude, but are not limited to, probes, amplification oligonucleotides,and antibodies. Particularly preferred compositions detect the level ofexpression (e.g., blood mRNA level, blood protein level) of a panel ofgenes. Systems and kits are provided that are useful, necessary, and/orsufficient for detecting expression of one or more genes.

Any of these compositions, alone or in combination with othercompositions of the present invention, may be provided in the form of akit or reagent mixture. For example, labeled probes and primer pairs areprovided in a kit for the amplification and detection and/orquantification of a panel of genes selected from those listed inTable 1. Kits may include any and all components necessary or sufficientfor assays including, but not limited to, detection reagents,amplification reagents, buffers, control reagents (e.g., tissue samples,positive and negative control sample, etc.), solid supports, labels,written and/or pictorial instructions and product information,inhibitors, labeling and/or detection reagents, package environmentalcontrols (e.g., ice, desiccants, etc.), and the like. In someembodiments, kits provide a sub-set of the required components, whereinit is expected that the user will supply the remaining components. Insome embodiments, the kits comprise two or more separate containerswherein each container houses a subset of the components to bedelivered.

In some embodiments, the present invention provides therapies fordiseases characterized by altered expression of disease markersidentified using the methods of the present invention. In particular,the present invention provides methods and compositions for monitoringthe effects of a candidate therapy and for selecting therapies forpatients.

In some embodiments, methods of treating post-traumatic stress statesare provided (e.g., following biomarker identification of a subject assuffering from post-traumatic stress). Suitable treatments includepsychotherapy (e.g., cognitive therapy, exposure therapy, eye movementdesensitization and reprocessing (EMDR), etc.) and medication (e.g.,antidepressants (e.g., selective serotonin reuptake inhibitors (SSRI)such as sertraline and paroxetine), anti-anxiety medications, prazosin,etc.).

In some embodiments, systems and devices are provided for implementingthe diagnostic methods described herein (e.g., data analysis,communication, result reporting, etc.). In some embodiments, a softwareor hardware component receives the results of multiple assays, factors,and/or biomarkers and determines a single value result to report to auser that indicates a conclusion (e.g., high risk PTSD, low risk ofPTSD, PTSD diagnosis, etc.). Related embodiments calculate a risk factorbased on a mathematical combination (e.g., a weighted combination, alinear combination) of the results from multiple assays, factors, and/orbiomarkers.

Some embodiments comprise a storage medium and memory components. Memorycomponents (e.g., volatile and/or nonvolatile memory) find use instoring instructions (e.g., an embodiment of a process as providedherein) and/or data. Some embodiments relate to systems also comprisingone or more of a CPU, a graphics card, and a user interface (e.g.,comprising an output device such as display and an input device such asa keyboard). Programmable machines associated with the technologycomprise conventional extant technologies and technologies indevelopment or yet to be developed (e.g., a quantum computer, a chemicalcomputer, a DNA computer, an optical computer, a spintronics basedcomputer, etc.). In some embodiments, the technology comprises a wired(e.g., metallic cable, fiber optic) or wireless transmission medium fortransmitting data. For example, some embodiments relate to datatransmission over a network (e.g., a local area network (LAN), a widearea network (WAN), an ad-hoc network, the internet, etc.). In someembodiments, programmable machines are present on such a network aspeers and in some embodiments the programmable machines have aclient/server relationship. In some embodiments, data are stored on acomputer-readable storage medium such as a hard disk, flash memory,optical media, a floppy disk, etc.

In some embodiments, the technology provided herein is associated with aplurality of programmable devices that operate in concert to perform amethod as described herein. For example, in some embodiments, aplurality of computers (e.g., connected by a network) may work inparallel to collect and process data, e.g., in an implementation ofcluster computing or grid computing or some other distributed computerarchitecture that relies on complete computers (with onboard CPUs,storage, power supplies, network interfaces, etc.) connected to anetwork (private, public, or the internet) by a conventional networkinterface, such as Ethernet, fiber optic, or by a wireless networktechnology.

Some embodiments provide a computer that includes a computer-readablemedium. The embodiment includes a random access memory (RAM) coupled toa processor. The processor executes computer-executable programinstructions stored in memory. Such processors may include amicroprocessor, an ASIC, a state machine, or other processor, and can beany of a number of computer processors, such as processors from IntelCorporation of Santa Clara, Calif. and Motorola Corporation ofSchaumburg, Ill. Such processors include, or may be in communicationwith, media, for example computer-readable media, which storesinstructions that, when executed by the processor, cause the processorto perform the steps described herein.

Embodiments of computer-readable media include, but are not limited to,an electronic, optical, magnetic, or other storage or transmissiondevice capable of providing a processor with computer-readableinstructions. Other examples of suitable media include, but are notlimited to, a floppy disk, CD-ROM, DVD, magnetic disk, memory chip, ROM,RAM, an ASIC, a configured processor, all optical media, all magnetictape or other magnetic media, or any other medium from which a computerprocessor can read instructions. Also, various other forms ofcomputer-readable media may transmit or carry instructions to acomputer, including a router, private or public network, or othertransmission device or channel, both wired and wireless. Theinstructions may comprise code from any suitable computer-programminglanguage, including, for example, C, C++, C#, Visual Basic, Java,Python, Perl, and JavaScript.

Computers are connected in some embodiments to a network. Computers mayalso include a number of external or internal devices such as a mouse, aCD-ROM, DVD, a keyboard, a display, or other input or output devices.Examples of computers are personal computers, digital assistants,personal digital assistants, cellular phones, mobile phones, smartphones, pagers, digital tablets, laptop computers, internet appliances,and other processor-based devices. In general, the computers related toaspects of the technology provided herein may be any type ofprocessor-based platform that operates on any operating system, such asMicrosoft Windows, Linux, UNIX, Mac OS X, etc., capable of supportingone or more programs comprising the technology provided herein. Someembodiments comprise a personal computer executing other applicationprograms (e.g., applications). The applications can be contained inmemory and can include, for example, a word processing application, aspreadsheet application, an email application, an instant messengerapplication, a presentation application, an Internet browserapplication, a calendar/organizer application, and any other applicationcapable of being executed by a client device.

All such components, computers, and systems described herein asassociated with the technology may be logical or virtual.

EXPERIMENTAL Example 1 Chronic Restraint Stress Experiments

Adult male Fisher 344, Brown-Norway, Lewis and Wistar Kyoto (WKY) ratswere obtained from Harlan lab and were housed individually. The control,no stress (NS) group remained in their home cage. Two groups of ratswere exposed to chronic restraint stress (CRS) in a breathabledecapicone for two hours per day, for a two-week period. On the 15thday, CRS rats were tested in the elevated plus maze (EPM) test, andsacrificed immediately after by decapitation. The post-stress, PCRSgroup were placed back to their home cage for 10 days, after which theywere tested in the EPM and sacrificed immediately. The NS control groupwent through EPM and decapitation in parallel with the CRS rats. Wholeblood was collected into PAXgene blood RNA tubes. Whole amygdali andhippocampi were dissected from the brains.

Blood RNA, amygdala RNA and hippocampal RNA were obtained and reversetranscribed to synthesize full-length cDNA, followed by second strandcDNA synthesis. For each sample, in-vitro transcription (IVT) reactionswere carried out incorporating biotinylated nucleotides according to themanufacturer's protocol for Illumina® Totalprep RNA amplification kit(Ambion). 1.5 μg biotin-labelled cRNA was then hybridized onto RatRef-12Expression BeadChips (Illumina, San Diego Calif.) for 16 hours at 55° C.Post-hybridization staining and washing were performed according tomanufacturer's protocols (Illumina). Illumina Sentrix ® RatRef-12 v1.0BeadChips were scanned using Illumina's BeadStation 500 scanner. Imageswere checked for grid alignment and then quantified using the BeadStudiosoftware. Control summary graphs generated by BeadStudio were used asquality assurance tools for hybridization, washing stringency, andbackground. Integrity of the arrays was investigated using the arrayimages. Mean pixel intensities by bead type, were created usingBeadStudio v3.1.

Probe intensity data from Illumina Chip arrays were read into the Rsoftware environment directly from bead summary files produced byBeadStudio using the R/beadarray package. Quantile normalization wasapplied to the Illumina bead summary data using the R/preprocessCorepackage. Data quality was assessed using histograms of signalintensities, scatterplots, and hierarchical clustering of samples.Analysis of variance (ANOVA) methods were used to statistically resolvegene expression differences using the R/maanova package.

The comparison between the different control strains (F344, BN and LEW)and the strain with endogenous/genetically determined depressivebehavior (WKY) was determined regarding the blood expression differencesbetween NS versus CRS and PCRS groups (Column 1, Table 1) and at thePCRS versus the NS groups (Columns 2-6, Table 1). When the samecomparisons were made for the amygdalar (A) or hippocampal (H) tissue,it was found that some of these differences are parallel to those in theblood. Therefore, the expression of these genes in the blood mirrorsexpression changes in these brain regions. These genes are marked inTable 1 with the superscript A and H.

The genes listed in Table 1 represent human genes, identified by theirmost frequently used names. The names of the rat ortholoques are oftendifferent.

TABLE 1 Candidate blood markers for PTSD (^(A) in amygdala, ^(H) inhippocampus as well) NS vs. PCRS NS vs CRS BN vs WKY & PCRS F344 vs LEWvs & LEW vs WKY vs WKY WKY WKY WKY WKY ALL ALOX15 ACTA1 ALG8 C1QTNF7IFI27^(A) SERPINB1^(A) BCL11B ACTN3 APBA3 CDH1 FUOM LILRB3^(A) CATADN^(A) ARFIP1 SLC9A9 HSPA8 GLRX CDR2 ADRP ARL6 DCAF17 IGK EGLN2ATP6V1G1 CCL28 SSPN LCMT1 EIF4G2 BRD9 CCR8 MYOG THYN1 ELOVL5^(A) BZRPCOIL PAK4 SEC14L2 ETS1 CKM COPEB PTPRM SLC16A3 FECH DEFA CYP21A1^(H)RTKN SERINC2 INPP5B DGAT2^(A) DSCR3 TRPM6 IRF7 FLOT2 GPHA2 XKRX ITKHNRPA3P2 HOXD10 JAK1 MIIP/IIP45 HSD17B12 TMEM199 CSTB IER2 NPM1 B9D2ALKBH4 PTP4A1 SPTB NUGGC RNF145 HSD17B12 IDI2 RPL41 VOPP1 FHOD1 SCD2STFA2 TAGAP SV2B PRR7 DPH7 TRA29 TPI1 HTRA4 TESTIN SWI5 QPCT UBE2G1 HSP8THSD4 USP25 ATP5H REPS2 ZFAND6 MX2 CD209 NALP12 GSTK1 OAS1 CPS1 PI3G3PDH PRDX6 C3ORF49 PROK2^(A) FAM107B PSP OTUD1 CD302 OSTM1 RHOA GLI4S100A8 GCOM1 SAS TRIM60 SLPI LYG2 TAPBPL MAP3K3 TNFRSF1A^(A) MCPT8L3TNNT3 METTL2 TPI1 NGB UBQLN1 ODF1 UGP2 OPLAH P34 P4HA1 PHF13 PIAS1 PRM1PVRL2 RALGDS RGS3 RPL34 RUNX1 SCAMP2 SEC61A2 SLC5A3 SOCS4 STAU1 SUSD3SYNJ1 TSN USP49 VAPB WIF1 ZFYVE26 RNF114 Genes listed above exhibited achange in blood transcript levels according to the following criteria,where “≠” indicates >25% difference in absolute transcript level, “=”indicates <25% difference in absolute transcript level: Column 1: NS ≠CRS = PCRS in WKY strain Column 2: NS = CRS ≠ PCRS in WKY strain Column3: (PCRS − NS in WKY) ≠ (PCRS − NS in F344) Column 4: (PCRS − NS in WKY)≠ (PCRS − NS in LEW) Column 5: (PCRS − NS in WKY) ≠ (PCRS − NS in F344and BN) Column 6: (PCRS − NS in WKY) ≠ (PCRS − NS in F344, LEW, and BN)Genes listed above exhibited a change in amygdalar (A) or hippocampal(H) transcript levels according to the same criteria as above.

All publications and patents provided herein incorporated by referencein their entireties. Various modifications and variations of thedescribed compositions and methods of the invention will be apparent tothose skilled in the art without departing from the scope and spirit ofthe invention. Although the invention has been described in connectionwith specific preferred embodiments, it should be understood that theinvention as claimed should not be unduly limited to such specificembodiments. Indeed, various modifications of the described modes forcarrying out the invention that are obvious to those skilled in therelevant fields are intended to be within the scope of the presentinvention.

I claim:
 1. A panel of biomarkers consisting of an isolated set of 100or fewer full-length cDNA biomarkers, wherein said isolated set includesSERPINB1, LILRB3, and GLRX full-length cDNA biomarkers.
 2. The panel ofbiomarkers of claim 1, comprising a full-length IFI27 cDNA biomarker. 3.The panel of biomarkers of claim 1, comprising a full-length FUOM cDNAbiomarker.
 4. The panel of biomarkers of claim 1, comprising afull-length HSPA8 cDNA biomarker.
 5. The panel of biomarkers of claim 1,comprising a full-length IGK cDNA biomarker.
 6. The panel of biomarkersof claim 1, comprising a full-length LCMT1 cDNA biomarker.
 7. The panelof biomarkers of claim 1, comprising a full-length THYN1 cDNA biomarker.8. The panel of biomarkers of claim 1, comprising a full-length SEC14L2cDNA biomarker.
 9. The panel of biomarkers of claim 1, comprising afull-length SLC16A3 cDNA biomarker.
 10. The panel of biomarkers of claim1, comprising a full-length SERINC2 cDNA biomarker.
 11. The panel ofbiomarkers of claim 1, comprising a full-length TRPM6 cDNA biomarker.12. The panel of biomarkers of claim 1, comprising a full-length XKRXcDNA biomarker.
 13. The panel of biomarkers of claim 1, comprising afull-length ADN cDNA biomarker.
 14. The panel of biomarkers of claim 1,comprising a full-length DGAT2 cDNA biomarker.
 15. The panel ofbiomarkers of claim 1, comprising a full-length PROK2 cDNA biomarker.16. The panel of biomarkers of claim 1, comprising a full-lengthTNFRSF1A cDNA biomarker.